OP: "Thanks for all the feedback. I think, personally, I’ll take rearward firing energy out of the equation and go with a conventional speaker design."
Conventional speakers also have rearward firing energy as well as a lot more energy hitting the side walls, floor and ceiling.
OP: "I’ve learned that everything, EVERYTHING makes a difference. The only question is how significant, and how audible is it."
Unless you have a room that is particularly unsuited for electrostats, and you would have to try them to know for sure, electrostats should not be more of a problem than other speaker designs. As you know, all speakers come with their own issues.